Risk Management, Derivative Instruments and Hedging Activities - Schedule of Net Notional Volumes of Open Commodity Derivatives and Interest Rate Derivatives (Details) $ in Millions |
9 Months Ended | 12 Months Ended |
|---|---|---|
|
Sep. 30, 2026
USD ($)
MMBTU
MWh
|
Dec. 31, 2025
USD ($)
MMBTU
MWh
|
|
| Commodity derivatives | Short | ||
| Derivative [Line Items] | ||
| Commodity purchase (sales) derivatives, power and natural gas | MWh | 82,616,910 | 59,634,723 |
| Commodity derivatives | Long | ||
| Derivative [Line Items] | ||
| Commodity purchase (sales) derivatives, power and natural gas | MMBTU | 253,213,772 | 169,209,022 |
| Interest rate derivatives | ||
| Derivative [Line Items] | ||
| Interest rate (in millions) | $ | $ 700 | $ 990 |